Building the right thing, building it right, fast

Who I am

My name is Jakub Holy and I’m a software craftsmanship enthusiast and a (mainly JVM-based) developer since ~ 2005, consultant, and occasionally a project manager, working currently with TeliaSonera AS in Norway. More under About and #opinion.

Two phase release planning – the best way to plan something somehow reliably is to just start doing it, i.e. just start the project with the objective of answering “Can this team produce a respectable implementation of that system by that date?” in as short time as possible (i.e. few weeks). Then: “Phase 2: At this point, there’s a commitment: a respectable product will be released on a particular date. Now those paying for the product have to accept a brute fact: they will not know, until close to that date, just what that product will look like (its feature list). What they do know is that it will be the best product this development team can produce by that date.” Final words: “My success selling this approach has been mixed. People really like the feeling of certainty, even if it’s based on nothing more than a grand collective pretending.”

Jay Fields’ Thoughts: Compatible Opinions on Software – about teams and opinion conflicts – there are some areas where no opinion is really right (e.g. powerful language vs. powerful IDE) yet people may have very strong feeling about them. Be aware of what your opinions are and how strong they are – and compose teams so that they include more less people with compatible (not same!) opinions – because if you team people with strong opposing opinions, they’ll loose lot of productivity. Quotes: “I also believe that you can have two technically excellent people who have vastly different opinions on the most effective way to deliver software.” “I suggest that you do your best to avoid working with someone who has both an opposing view and is as inflexible as you are on the subject. The more central the subject is to the project, the more likely it is that productivity will be lost.”

JBoss Byteman 2.0.0: Bytecode Manipulation, Testing, Fault Injection, Logging – a Java agent which helps testing, tracing, and monitoring code, code is injected based on simple scripts (rules) in the event-condition-action form (the conditions may use counters, timers etc.). Contrary to AOP, there is no need to create classes or compile code. “Byteman is also simpler to use and easier to change, especially for testing and ad hoc logging purposes.” “Byteman was invented primarily to support automation of tests for multi-threaded and multi-JVM Java applications using a technique called fault injection.” It was used e.g. to orchestrate the timing of activities performed by independent threads, for monitoring and statistics gathering, for application testing via fault injection. Contains a JUnit4 Runner for easily instrumenting the code under test, it can automatically load a rule before a test and unload it afterwards:

How should code search work? – a thought-provoking article about how much better code completion could be if it profited more from patterns of usage in existing source codes – and how to achieve that. Intermediate results available in the Code Recommenders Eclipse plugin.

How to GET a Cup of Coffee, 10/2008 – good introduction into creating applications based on REST, explained on an example of building REST workflow for the ordering process in Starbucks – a “self-describing state machine”. The advantage of this article is that it presents the whole REST workflow with GET, OPTIONS, POST, PUT and “advanced” features such as the use of If-Unmodified-Since/If-Match, Precondition Failed, Conflict. The workflow steps are connected via the Location header and a custom <next> link tag with rel and uri. Other keywords: etag, microformats, HATEOS (-> derive the next resource to access from the links in the previous one), Atom and AtomPub, caching (web trades latency for scaleability; if 1+s latency isn’t acceptable than web isn’t the right platform), URI templates (-> more coupling than links in responses), evolution (-> links from responses, new transitions), idempotency. “The Web is a robust framework for integrating systems at local, enterprise, and Internet scale.”

Links to Keep

Tools, Libraries etc.

ClusterSSH – whatever commands you execute in the master SSH session are also execute in the slave sessions – useful if you often need to execute the same thing on multiple machines (requires Perl); to install on Mac: “brew install csshx”

Twitter Finagle – “library to implement asynchronous Remote Procedure Call (RPC) clients and servers. Finagle is flexible enough to support a variety of RPC styles, including request-response, streaming, and pipelining; for example, HTTP pipelining and Redis pipelining. It also makes it easy to work with stateful RPC styles; for example, RPCs that require authentication and those that support transactions.” Supports also failover/retry, service discovery, multiple protocol (e.g. http, thrift). Build on Netty, Java NIO. See the overview and architecture.

Eclipse Code Recommenders – interesting plugin in incubation that tries to bring more more intelligent completion based more on context and the wisdom of the crowds (i.e. patterns of usage in existing source codes) to Eclipse

Clojure Corner

Clojure/huh? – Clojure’s Governance and How It Got That Way – an interesting description how the development of Clojure and inclusion of new libraries is managed. “Rich is extremely conservative about adding features to the language, and he has impressed this view on Clojure/core for the purpose of screening tickets.” E.g. it took two years to get support for named arguments – but the result is a much better and cleaner way of doing it.

Quotes

A language that doesn’t affect the way you think about programming, is not worth knowing-

– Alan Perlis

Lisp is worth learning for the profound enlightenment experience you will have when you finally get it; that experience will make you a better programmer for the rest of your days, even if you never actually use Lisp itself a lot.